Identity-based policy examples for Amazon Managed Blockchain (AMB) Access Ethereum

By default, users and roles don't have permission to create or modify AMB Access Ethereum resources. They also can't perform tasks by using the AWS Management Console, AWS Command Line Interface (AWS CLI), or AWS API. To grant users permission to perform actions on the resources that they need, an IAM administrator can create IAM policies. The administrator can then add the IAM policies to roles, and users can assume the roles.

To learn how to create an IAM identity-based policy by using these example JSON policy documents, see Creating IAM policies in the IAM User Guide.

For details about actions and resource types defined by AMB Access Ethereum, including the format of the ARNs for each of the resource types, see Actions, resources, and condition keys for Amazon Managed Blockchain (AMB) Access Ethereum in the Service Authorization Reference.

Policy best practices

Identity-based policies determine whether someone can create, access, or delete AMB Access Ethereum resources in your account. These actions can incur costs for your AWS account. When you create or edit identity-based policies, follow these guidelines and recommendations:

• Get started with AWS managed policies and move toward least-privilege permissions – To get started granting permissions to your users and workloads, use the AWS managed policies that grant permissions for many common use cases. They are available in your AWS account. We recommend that you reduce permissions further by defining AWS customer managed policies that are specific to your use cases. For more information, see AWS managed policies or AWS managed policies for job functions in the IAM User Guide.

• Apply least-privilege permissions – When you set permissions with IAM policies, grant only the permissions required to perform a task. You do this by defining the actions that can be taken on specific resources under specific conditions, also known as least-privilege permissions. For more information about using IAM to apply permissions, see Policies and permissions in IAM in the IAM User Guide.

• Use conditions in IAM policies to further restrict access – You can add a condition to your policies to limit access to actions and resources. For example, you can write a policy condition to specify that all requests must be sent using SSL. You can also use conditions to grant access to service actions if they are used through a specific AWS service, such as AWS CloudFormation. For more information, see IAM JSON policy elements: Condition in the IAM User Guide.

• Use IAM Access Analyzer to validate your IAM policies to ensure secure and functional permissions – IAM Access Analyzer validates new and existing policies so that the policies adhere to the IAM policy language (JSON) and IAM best practices. IAM Access Analyzer provides more than 100 policy checks and actionable recommendations to help you author secure and functional policies. For more information, see IAM Access Analyzer policy validation in the IAM User Guide.

• Require multi-factor authentication (MFA) – If you have a scenario that requires IAM users or a root user in your AWS account, turn on MFA for additional security. To require MFA when API operations are called, add MFA conditions to your policies. For more information, see Configuring MFA-protected API access in the IAM User Guide.

For more information about best practices in IAM, see Security best practices in IAM in the IAM User Guide.

Using the AMB Access Ethereum console

To access the Amazon Managed Blockchain (AMB) Access Ethereum console, you must have a minimum set of permissions. These permissions must allow you to list and view details about the AMB Access Ethereum resources in your AWS account. If you create an identity-based policy that is more restrictive than the minimum required permissions, the console won't function as intended for entities (users or roles) with that policy.

You don't need to allow minimum console permissions for users that are making calls only to the AWS CLI or the AWS API. Instead, allow access to only the actions that match the API operation that they're trying to perform.

To ensure that users and roles can still use the AMB Access Ethereum console, also attach the AMB Access Ethereum ConsoleAccess or ReadOnly AWS managed policy to the entities. For more information, see Adding permissions to a user in the IAM User Guide.

AmazonManagedBlockchainConsoleFullAccess

Allow users to view their own permissions

This example shows how you might create a policy that allows IAM users to view the inline and managed policies that are attached to their user identity. This policy includes permissions to complete this action on the console or programmatically using the AWS CLI or AWS API.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ViewOwnUserInfo",
            "Effect": "Allow",
            "Action": [
                "iam:GetUserPolicy",
                "iam:ListGroupsForUser",
                "iam:ListAttachedUserPolicies",
                "iam:ListUserPolicies",
                "iam:GetUser"
            ],
            "Resource": ["arn:aws:iam::*:user/${aws:username}"]
        },
        {
            "Sid": "NavigateInConsole",
            "Effect": "Allow",
            "Action": [
                "iam:GetGroupPolicy",
                "iam:GetPolicyVersion",
                "iam:GetPolicy",
                "iam:ListAttachedGroupPolicies",
                "iam:ListGroupPolicies",
                "iam:ListPolicyVersions",
                "iam:ListPolicies",
                "iam:ListUsers"
            ],
            "Resource": "*"
        }
    ]
}

Performing all available actions for AMB Access Ethereum

This example shows how you grant users AWS account access in the us-east-1 Region so that they can do the following:

• List all Ethereum networks

• Create and list nodes on all those networks

• Get and delete nodes in AWS account 111122223333

• Get and delete accessors in AWS account 555555555555

• Create WebSocket connections, and send HTTP requests to an Ethereum node

Note

• If you want to grant access across all Regions, replace us-east-1 with *.

• You must specify the AWS account ID of the node and accessor resources in the policy that you want to enforce.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "WorkWithEthereumNetworks",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:ListNetworks",
                "managedblockchain:GetNetwork"
            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1::networks/n-ethereum-mainnet"
                
                
            ]
        },
        {
            "Sid": "CreateAndListEthereumNodes",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:CreateNode",
                "managedblockchain:ListNodes"
            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1::networks/*"
            ]
        },
        {
            "Sid": "ManageEthereumNodes",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:GetNode",
                "managedblockchain:DeleteNode"
            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1:111122223333:nodes/*"
            ]
        },
         {
            "Sid": "GetAndDeleteAccessors",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:GetAccessor",
                "managedblockchain:DeleteAccessor"
            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1:555555555555:accessors/*"
            ]
        },
        {
            "Sid": "CreateAndListAccessors",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:CreateAccessor",
                "managedblockchain:ListAccessors"
            ],
            "Resource": [
                "*"
            ]
        },       
        {
            "Sid": "WorkWithEthereumNodes",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:POST",
                "managedblockchain:GET",
                "managedblockchain:Invoke"

            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1:111122223333:*"
             ]
        }
    ]
}

Controlling access using tags

The following example policies demonstrate how you can use tags to limit access to AMB Access Ethereum resources and actions performed on those resources.

Note

This topic includes examples of policy statements with a Deny effect. These policies assume that other policies with Allow effect for those actions exist with broader applicability. The Deny policy statement is being used to restrict that otherwise overly-permissive allow statement.

Example – Deny access to networks with a specific tag key

The following identity-based policy statement denies the IAM principal the ability to retrieve or view network information if the network has a tag with the tag key of restricted.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DenyTaggedNetworkAccess",
            "Effect": "Deny",
            "Action": [
                "managedblockchain:GetNetwork"
            ],
            "Resource": [
                "*"
            ],
            "Condition": {
                "StringLike": {
                    "aws:ResourceTag/restricted": [
                        "*"
                    ]
                }
            }
        }
    ]
}

Example – Deny node creation on networks that have a specific tag and value

The following identity-based policy statement denies the IAM principal the ability to create a node on an Ethereum public network tagged in the AWS account with the tag key of department and the value accounting.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DenyCreateNodeForNetworkWithTag",
            "Effect": "Deny",
            "Action": [
                "managedblockchain:CreateNode"
            ],
            "Resource": [
                "*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:ResourceTag/department": [
                        "accounting"
                    ]
                }
            }
        }
    ]
}

Example – Require a specific tag key and value to be added when a node is created

The following identity-based policy statements allow an IAM principal to create a node for the AWS account 111122223333 only if a key with the tag key of department and a value of accounting is added during creation.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "RequireTagForCreateNode",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:CreateNode"
            ],
            "Resource": [
                "*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:RequestTag/department": [
                        "accounting"
                    ]
                }
            }
        },
        {
            "Sid": "AllowTaggingNodes",
            "Effect": "Allow",
            "Action": [
                "managedblockchain:TagResource"
            ],
            "Resource": [
                "arn:aws:managedblockchain:us-east-1:111122223333:nodes/*"
            ]
        }
    ]
}

Example – Deny listing nodes for networks that have a specific tag key and value

The following identity-based policy statement denies the IAM principal the ability to list nodes on an Ethereum public network tagged in the AWS account with the tag key of department and the value accounting.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DenyListNodesForNetworkWithTag",
            "Effect": "Deny",
            "Action": [
                "managedblockchain:ListNodes"
            ],
            "Resource": [
                "*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:ResourceTag/department": [
                        "accounting"
                    ]
                }
            }
        }
    ]
}

Example – Deny retrieving and viewing node information for nodes with a specific tag key and value

The following identity-based policy statement denies the IAM principal the ability to view node information for nodes that have a tag with the tag key of department and the value accounting.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DenyGetNodeWithNodeTag",
            "Effect": "Deny",
            "Action": [
                "managedblockchain:GetNode"
            ],
            "Resource": [
                "*"
            ],
            "Condition": {
                "StringEquals": {
                    "aws:ResourceTag/department": [
                        "accounting"
                    ]
                }
            }
        }
    ]
}